A relationship has been established between selenium intake and cancer at numerous sites in experimental animals and an association has been suggested between selenium intake and pancreatic cancer in man. The development of an appropriate pancreatic cancer model in the Syrian golden hamster at our institute has made it possible to evaluate the possible influence of dietary selenium on experimental pancreatic cancer. This application proposes short-term and chronic studies which will evaluate this relationship. In the short-term study, the selenium requirement and the effects of selenium deprivation and excess will be determined in the Syrian hamster. Data from this study will be utilized to establish selenium levels to feed in a life-span study on pancreatic carcinogenesis. The effects of the type of dietary selenium will be evaluated by feeding sodium selenite and seleno DL methionine. The influence of excess and restriction will be observed, and the effects of feeding these levels before and after treatment with the carcinogen will be determined. In addition, these studies will evaluate the effects of life-span feeding of three levels of selenium (a proposed anticarcinogen) on longevity and general health in the Syrian golden hamster.